xref: /qemu/system/arch_init.c (revision 474ddaf6e3aebc470f4665ef4f7ce6578448c6d1)
1 /*
2  * QEMU System Emulator
3  *
4  * Copyright (c) 2003-2008 Fabrice Bellard
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22  * THE SOFTWARE.
23  */
24 #include <stdint.h>
25 #include <stdarg.h>
26 #include <stdlib.h>
27 #include <zlib.h>
28 #ifndef _WIN32
29 #include <sys/types.h>
30 #include <sys/mman.h>
31 #endif
32 #include "config.h"
33 #include "monitor/monitor.h"
34 #include "sysemu/sysemu.h"
35 #include "qemu/bitops.h"
36 #include "qemu/bitmap.h"
37 #include "sysemu/arch_init.h"
38 #include "audio/audio.h"
39 #include "hw/i386/pc.h"
40 #include "hw/pci/pci.h"
41 #include "hw/audio/audio.h"
42 #include "sysemu/kvm.h"
43 #include "migration/migration.h"
44 #include "hw/i386/smbios.h"
45 #include "exec/address-spaces.h"
46 #include "hw/audio/pcspk.h"
47 #include "migration/page_cache.h"
48 #include "qemu/config-file.h"
49 #include "qemu/error-report.h"
50 #include "qmp-commands.h"
51 #include "trace.h"
52 #include "exec/cpu-all.h"
53 #include "exec/ram_addr.h"
54 #include "hw/acpi/acpi.h"
55 #include "qemu/host-utils.h"
56 #include "qemu/rcu_queue.h"
57 
58 #ifdef DEBUG_ARCH_INIT
59 #define DPRINTF(fmt, ...) \
60     do { fprintf(stdout, "arch_init: " fmt, ## __VA_ARGS__); } while (0)
61 #else
62 #define DPRINTF(fmt, ...) \
63     do { } while (0)
64 #endif
65 
66 #ifdef TARGET_SPARC
67 int graphic_width = 1024;
68 int graphic_height = 768;
69 int graphic_depth = 8;
70 #else
71 int graphic_width = 800;
72 int graphic_height = 600;
73 int graphic_depth = 32;
74 #endif
75 
76 
77 #if defined(TARGET_ALPHA)
78 #define QEMU_ARCH QEMU_ARCH_ALPHA
79 #elif defined(TARGET_ARM)
80 #define QEMU_ARCH QEMU_ARCH_ARM
81 #elif defined(TARGET_CRIS)
82 #define QEMU_ARCH QEMU_ARCH_CRIS
83 #elif defined(TARGET_I386)
84 #define QEMU_ARCH QEMU_ARCH_I386
85 #elif defined(TARGET_M68K)
86 #define QEMU_ARCH QEMU_ARCH_M68K
87 #elif defined(TARGET_LM32)
88 #define QEMU_ARCH QEMU_ARCH_LM32
89 #elif defined(TARGET_MICROBLAZE)
90 #define QEMU_ARCH QEMU_ARCH_MICROBLAZE
91 #elif defined(TARGET_MIPS)
92 #define QEMU_ARCH QEMU_ARCH_MIPS
93 #elif defined(TARGET_MOXIE)
94 #define QEMU_ARCH QEMU_ARCH_MOXIE
95 #elif defined(TARGET_OPENRISC)
96 #define QEMU_ARCH QEMU_ARCH_OPENRISC
97 #elif defined(TARGET_PPC)
98 #define QEMU_ARCH QEMU_ARCH_PPC
99 #elif defined(TARGET_S390X)
100 #define QEMU_ARCH QEMU_ARCH_S390X
101 #elif defined(TARGET_SH4)
102 #define QEMU_ARCH QEMU_ARCH_SH4
103 #elif defined(TARGET_SPARC)
104 #define QEMU_ARCH QEMU_ARCH_SPARC
105 #elif defined(TARGET_XTENSA)
106 #define QEMU_ARCH QEMU_ARCH_XTENSA
107 #elif defined(TARGET_UNICORE32)
108 #define QEMU_ARCH QEMU_ARCH_UNICORE32
109 #elif defined(TARGET_TRICORE)
110 #define QEMU_ARCH QEMU_ARCH_TRICORE
111 #endif
112 
113 const uint32_t arch_type = QEMU_ARCH;
114 static bool mig_throttle_on;
115 static int dirty_rate_high_cnt;
116 static void check_guest_throttling(void);
117 
118 static uint64_t bitmap_sync_count;
119 
120 /***********************************************************/
121 /* ram save/restore */
122 
123 #define RAM_SAVE_FLAG_FULL     0x01 /* Obsolete, not used anymore */
124 #define RAM_SAVE_FLAG_COMPRESS 0x02
125 #define RAM_SAVE_FLAG_MEM_SIZE 0x04
126 #define RAM_SAVE_FLAG_PAGE     0x08
127 #define RAM_SAVE_FLAG_EOS      0x10
128 #define RAM_SAVE_FLAG_CONTINUE 0x20
129 #define RAM_SAVE_FLAG_XBZRLE   0x40
130 /* 0x80 is reserved in migration.h start with 0x100 next */
131 #define RAM_SAVE_FLAG_COMPRESS_PAGE    0x100
132 
133 static struct defconfig_file {
134     const char *filename;
135     /* Indicates it is an user config file (disabled by -no-user-config) */
136     bool userconfig;
137 } default_config_files[] = {
138     { CONFIG_QEMU_CONFDIR "/qemu.conf",                   true },
139     { CONFIG_QEMU_CONFDIR "/target-" TARGET_NAME ".conf", true },
140     { NULL }, /* end of list */
141 };
142 
143 static const uint8_t ZERO_TARGET_PAGE[TARGET_PAGE_SIZE];
144 
145 int qemu_read_default_config_files(bool userconfig)
146 {
147     int ret;
148     struct defconfig_file *f;
149 
150     for (f = default_config_files; f->filename; f++) {
151         if (!userconfig && f->userconfig) {
152             continue;
153         }
154         ret = qemu_read_config_file(f->filename);
155         if (ret < 0 && ret != -ENOENT) {
156             return ret;
157         }
158     }
159 
160     return 0;
161 }
162 
163 static inline bool is_zero_range(uint8_t *p, uint64_t size)
164 {
165     return buffer_find_nonzero_offset(p, size) == size;
166 }
167 
168 /* struct contains XBZRLE cache and a static page
169    used by the compression */
170 static struct {
171     /* buffer used for XBZRLE encoding */
172     uint8_t *encoded_buf;
173     /* buffer for storing page content */
174     uint8_t *current_buf;
175     /* Cache for XBZRLE, Protected by lock. */
176     PageCache *cache;
177     QemuMutex lock;
178 } XBZRLE;
179 
180 /* buffer used for XBZRLE decoding */
181 static uint8_t *xbzrle_decoded_buf;
182 
183 static void XBZRLE_cache_lock(void)
184 {
185     if (migrate_use_xbzrle())
186         qemu_mutex_lock(&XBZRLE.lock);
187 }
188 
189 static void XBZRLE_cache_unlock(void)
190 {
191     if (migrate_use_xbzrle())
192         qemu_mutex_unlock(&XBZRLE.lock);
193 }
194 
195 /*
196  * called from qmp_migrate_set_cache_size in main thread, possibly while
197  * a migration is in progress.
198  * A running migration maybe using the cache and might finish during this
199  * call, hence changes to the cache are protected by XBZRLE.lock().
200  */
201 int64_t xbzrle_cache_resize(int64_t new_size)
202 {
203     PageCache *new_cache;
204     int64_t ret;
205 
206     if (new_size < TARGET_PAGE_SIZE) {
207         return -1;
208     }
209 
210     XBZRLE_cache_lock();
211 
212     if (XBZRLE.cache != NULL) {
213         if (pow2floor(new_size) == migrate_xbzrle_cache_size()) {
214             goto out_new_size;
215         }
216         new_cache = cache_init(new_size / TARGET_PAGE_SIZE,
217                                         TARGET_PAGE_SIZE);
218         if (!new_cache) {
219             error_report("Error creating cache");
220             ret = -1;
221             goto out;
222         }
223 
224         cache_fini(XBZRLE.cache);
225         XBZRLE.cache = new_cache;
226     }
227 
228 out_new_size:
229     ret = pow2floor(new_size);
230 out:
231     XBZRLE_cache_unlock();
232     return ret;
233 }
234 
235 /* accounting for migration statistics */
236 typedef struct AccountingInfo {
237     uint64_t dup_pages;
238     uint64_t skipped_pages;
239     uint64_t norm_pages;
240     uint64_t iterations;
241     uint64_t xbzrle_bytes;
242     uint64_t xbzrle_pages;
243     uint64_t xbzrle_cache_miss;
244     double xbzrle_cache_miss_rate;
245     uint64_t xbzrle_overflows;
246 } AccountingInfo;
247 
248 static AccountingInfo acct_info;
249 
250 static void acct_clear(void)
251 {
252     memset(&acct_info, 0, sizeof(acct_info));
253 }
254 
255 uint64_t dup_mig_bytes_transferred(void)
256 {
257     return acct_info.dup_pages * TARGET_PAGE_SIZE;
258 }
259 
260 uint64_t dup_mig_pages_transferred(void)
261 {
262     return acct_info.dup_pages;
263 }
264 
265 uint64_t skipped_mig_bytes_transferred(void)
266 {
267     return acct_info.skipped_pages * TARGET_PAGE_SIZE;
268 }
269 
270 uint64_t skipped_mig_pages_transferred(void)
271 {
272     return acct_info.skipped_pages;
273 }
274 
275 uint64_t norm_mig_bytes_transferred(void)
276 {
277     return acct_info.norm_pages * TARGET_PAGE_SIZE;
278 }
279 
280 uint64_t norm_mig_pages_transferred(void)
281 {
282     return acct_info.norm_pages;
283 }
284 
285 uint64_t xbzrle_mig_bytes_transferred(void)
286 {
287     return acct_info.xbzrle_bytes;
288 }
289 
290 uint64_t xbzrle_mig_pages_transferred(void)
291 {
292     return acct_info.xbzrle_pages;
293 }
294 
295 uint64_t xbzrle_mig_pages_cache_miss(void)
296 {
297     return acct_info.xbzrle_cache_miss;
298 }
299 
300 double xbzrle_mig_cache_miss_rate(void)
301 {
302     return acct_info.xbzrle_cache_miss_rate;
303 }
304 
305 uint64_t xbzrle_mig_pages_overflow(void)
306 {
307     return acct_info.xbzrle_overflows;
308 }
309 
310 /* This is the last block that we have visited serching for dirty pages
311  */
312 static RAMBlock *last_seen_block;
313 /* This is the last block from where we have sent data */
314 static RAMBlock *last_sent_block;
315 static ram_addr_t last_offset;
316 static unsigned long *migration_bitmap;
317 static uint64_t migration_dirty_pages;
318 static uint32_t last_version;
319 static bool ram_bulk_stage;
320 
321 struct CompressParam {
322     bool start;
323     bool done;
324     QEMUFile *file;
325     QemuMutex mutex;
326     QemuCond cond;
327     RAMBlock *block;
328     ram_addr_t offset;
329 };
330 typedef struct CompressParam CompressParam;
331 
332 struct DecompressParam {
333     /* To be done */
334 };
335 typedef struct DecompressParam DecompressParam;
336 
337 static CompressParam *comp_param;
338 static QemuThread *compress_threads;
339 /* comp_done_cond is used to wake up the migration thread when
340  * one of the compression threads has finished the compression.
341  * comp_done_lock is used to co-work with comp_done_cond.
342  */
343 static QemuMutex *comp_done_lock;
344 static QemuCond *comp_done_cond;
345 /* The empty QEMUFileOps will be used by file in CompressParam */
346 static const QEMUFileOps empty_ops = { };
347 static bool quit_comp_thread;
348 static bool quit_decomp_thread;
349 static DecompressParam *decomp_param;
350 static QemuThread *decompress_threads;
351 static uint8_t *compressed_data_buf;
352 
353 static void *do_data_compress(void *opaque)
354 {
355     while (!quit_comp_thread) {
356 
357     /* To be done */
358 
359     }
360 
361     return NULL;
362 }
363 
364 static inline void terminate_compression_threads(void)
365 {
366     quit_comp_thread = true;
367 
368     /* To be done */
369 }
370 
371 void migrate_compress_threads_join(void)
372 {
373     int i, thread_count;
374 
375     if (!migrate_use_compression()) {
376         return;
377     }
378     terminate_compression_threads();
379     thread_count = migrate_compress_threads();
380     for (i = 0; i < thread_count; i++) {
381         qemu_thread_join(compress_threads + i);
382         qemu_fclose(comp_param[i].file);
383         qemu_mutex_destroy(&comp_param[i].mutex);
384         qemu_cond_destroy(&comp_param[i].cond);
385     }
386     qemu_mutex_destroy(comp_done_lock);
387     qemu_cond_destroy(comp_done_cond);
388     g_free(compress_threads);
389     g_free(comp_param);
390     g_free(comp_done_cond);
391     g_free(comp_done_lock);
392     compress_threads = NULL;
393     comp_param = NULL;
394     comp_done_cond = NULL;
395     comp_done_lock = NULL;
396 }
397 
398 void migrate_compress_threads_create(void)
399 {
400     int i, thread_count;
401 
402     if (!migrate_use_compression()) {
403         return;
404     }
405     quit_comp_thread = false;
406     thread_count = migrate_compress_threads();
407     compress_threads = g_new0(QemuThread, thread_count);
408     comp_param = g_new0(CompressParam, thread_count);
409     comp_done_cond = g_new0(QemuCond, 1);
410     comp_done_lock = g_new0(QemuMutex, 1);
411     qemu_cond_init(comp_done_cond);
412     qemu_mutex_init(comp_done_lock);
413     for (i = 0; i < thread_count; i++) {
414         /* com_param[i].file is just used as a dummy buffer to save data, set
415          * it's ops to empty.
416          */
417         comp_param[i].file = qemu_fopen_ops(NULL, &empty_ops);
418         qemu_mutex_init(&comp_param[i].mutex);
419         qemu_cond_init(&comp_param[i].cond);
420         qemu_thread_create(compress_threads + i, "compress",
421                            do_data_compress, comp_param + i,
422                            QEMU_THREAD_JOINABLE);
423     }
424 }
425 
426 /**
427  * save_page_header: Write page header to wire
428  *
429  * If this is the 1st block, it also writes the block identification
430  *
431  * Returns: Number of bytes written
432  *
433  * @f: QEMUFile where to send the data
434  * @block: block that contains the page we want to send
435  * @offset: offset inside the block for the page
436  *          in the lower bits, it contains flags
437  */
438 static size_t save_page_header(QEMUFile *f, RAMBlock *block, ram_addr_t offset)
439 {
440     size_t size;
441 
442     qemu_put_be64(f, offset);
443     size = 8;
444 
445     if (!(offset & RAM_SAVE_FLAG_CONTINUE)) {
446         qemu_put_byte(f, strlen(block->idstr));
447         qemu_put_buffer(f, (uint8_t *)block->idstr,
448                         strlen(block->idstr));
449         size += 1 + strlen(block->idstr);
450     }
451     return size;
452 }
453 
454 /* Update the xbzrle cache to reflect a page that's been sent as all 0.
455  * The important thing is that a stale (not-yet-0'd) page be replaced
456  * by the new data.
457  * As a bonus, if the page wasn't in the cache it gets added so that
458  * when a small write is made into the 0'd page it gets XBZRLE sent
459  */
460 static void xbzrle_cache_zero_page(ram_addr_t current_addr)
461 {
462     if (ram_bulk_stage || !migrate_use_xbzrle()) {
463         return;
464     }
465 
466     /* We don't care if this fails to allocate a new cache page
467      * as long as it updated an old one */
468     cache_insert(XBZRLE.cache, current_addr, ZERO_TARGET_PAGE,
469                  bitmap_sync_count);
470 }
471 
472 #define ENCODING_FLAG_XBZRLE 0x1
473 
474 /**
475  * save_xbzrle_page: compress and send current page
476  *
477  * Returns: 1 means that we wrote the page
478  *          0 means that page is identical to the one already sent
479  *          -1 means that xbzrle would be longer than normal
480  *
481  * @f: QEMUFile where to send the data
482  * @current_data:
483  * @current_addr:
484  * @block: block that contains the page we want to send
485  * @offset: offset inside the block for the page
486  * @last_stage: if we are at the completion stage
487  * @bytes_transferred: increase it with the number of transferred bytes
488  */
489 static int save_xbzrle_page(QEMUFile *f, uint8_t **current_data,
490                             ram_addr_t current_addr, RAMBlock *block,
491                             ram_addr_t offset, bool last_stage,
492                             uint64_t *bytes_transferred)
493 {
494     int encoded_len = 0, bytes_xbzrle;
495     uint8_t *prev_cached_page;
496 
497     if (!cache_is_cached(XBZRLE.cache, current_addr, bitmap_sync_count)) {
498         acct_info.xbzrle_cache_miss++;
499         if (!last_stage) {
500             if (cache_insert(XBZRLE.cache, current_addr, *current_data,
501                              bitmap_sync_count) == -1) {
502                 return -1;
503             } else {
504                 /* update *current_data when the page has been
505                    inserted into cache */
506                 *current_data = get_cached_data(XBZRLE.cache, current_addr);
507             }
508         }
509         return -1;
510     }
511 
512     prev_cached_page = get_cached_data(XBZRLE.cache, current_addr);
513 
514     /* save current buffer into memory */
515     memcpy(XBZRLE.current_buf, *current_data, TARGET_PAGE_SIZE);
516 
517     /* XBZRLE encoding (if there is no overflow) */
518     encoded_len = xbzrle_encode_buffer(prev_cached_page, XBZRLE.current_buf,
519                                        TARGET_PAGE_SIZE, XBZRLE.encoded_buf,
520                                        TARGET_PAGE_SIZE);
521     if (encoded_len == 0) {
522         DPRINTF("Skipping unmodified page\n");
523         return 0;
524     } else if (encoded_len == -1) {
525         DPRINTF("Overflow\n");
526         acct_info.xbzrle_overflows++;
527         /* update data in the cache */
528         if (!last_stage) {
529             memcpy(prev_cached_page, *current_data, TARGET_PAGE_SIZE);
530             *current_data = prev_cached_page;
531         }
532         return -1;
533     }
534 
535     /* we need to update the data in the cache, in order to get the same data */
536     if (!last_stage) {
537         memcpy(prev_cached_page, XBZRLE.current_buf, TARGET_PAGE_SIZE);
538     }
539 
540     /* Send XBZRLE based compressed page */
541     bytes_xbzrle = save_page_header(f, block, offset | RAM_SAVE_FLAG_XBZRLE);
542     qemu_put_byte(f, ENCODING_FLAG_XBZRLE);
543     qemu_put_be16(f, encoded_len);
544     qemu_put_buffer(f, XBZRLE.encoded_buf, encoded_len);
545     bytes_xbzrle += encoded_len + 1 + 2;
546     acct_info.xbzrle_pages++;
547     acct_info.xbzrle_bytes += bytes_xbzrle;
548     *bytes_transferred += bytes_xbzrle;
549 
550     return 1;
551 }
552 
553 static inline
554 ram_addr_t migration_bitmap_find_and_reset_dirty(MemoryRegion *mr,
555                                                  ram_addr_t start)
556 {
557     unsigned long base = mr->ram_addr >> TARGET_PAGE_BITS;
558     unsigned long nr = base + (start >> TARGET_PAGE_BITS);
559     uint64_t mr_size = TARGET_PAGE_ALIGN(memory_region_size(mr));
560     unsigned long size = base + (mr_size >> TARGET_PAGE_BITS);
561 
562     unsigned long next;
563 
564     if (ram_bulk_stage && nr > base) {
565         next = nr + 1;
566     } else {
567         next = find_next_bit(migration_bitmap, size, nr);
568     }
569 
570     if (next < size) {
571         clear_bit(next, migration_bitmap);
572         migration_dirty_pages--;
573     }
574     return (next - base) << TARGET_PAGE_BITS;
575 }
576 
577 static inline bool migration_bitmap_set_dirty(ram_addr_t addr)
578 {
579     bool ret;
580     int nr = addr >> TARGET_PAGE_BITS;
581 
582     ret = test_and_set_bit(nr, migration_bitmap);
583 
584     if (!ret) {
585         migration_dirty_pages++;
586     }
587     return ret;
588 }
589 
590 static void migration_bitmap_sync_range(ram_addr_t start, ram_addr_t length)
591 {
592     ram_addr_t addr;
593     unsigned long page = BIT_WORD(start >> TARGET_PAGE_BITS);
594 
595     /* start address is aligned at the start of a word? */
596     if (((page * BITS_PER_LONG) << TARGET_PAGE_BITS) == start) {
597         int k;
598         int nr = BITS_TO_LONGS(length >> TARGET_PAGE_BITS);
599         unsigned long *src = ram_list.dirty_memory[DIRTY_MEMORY_MIGRATION];
600 
601         for (k = page; k < page + nr; k++) {
602             if (src[k]) {
603                 unsigned long new_dirty;
604                 new_dirty = ~migration_bitmap[k];
605                 migration_bitmap[k] |= src[k];
606                 new_dirty &= src[k];
607                 migration_dirty_pages += ctpopl(new_dirty);
608                 src[k] = 0;
609             }
610         }
611     } else {
612         for (addr = 0; addr < length; addr += TARGET_PAGE_SIZE) {
613             if (cpu_physical_memory_get_dirty(start + addr,
614                                               TARGET_PAGE_SIZE,
615                                               DIRTY_MEMORY_MIGRATION)) {
616                 cpu_physical_memory_reset_dirty(start + addr,
617                                                 TARGET_PAGE_SIZE,
618                                                 DIRTY_MEMORY_MIGRATION);
619                 migration_bitmap_set_dirty(start + addr);
620             }
621         }
622     }
623 }
624 
625 
626 /* Fix me: there are too many global variables used in migration process. */
627 static int64_t start_time;
628 static int64_t bytes_xfer_prev;
629 static int64_t num_dirty_pages_period;
630 
631 static void migration_bitmap_sync_init(void)
632 {
633     start_time = 0;
634     bytes_xfer_prev = 0;
635     num_dirty_pages_period = 0;
636 }
637 
638 /* Called with iothread lock held, to protect ram_list.dirty_memory[] */
639 static void migration_bitmap_sync(void)
640 {
641     RAMBlock *block;
642     uint64_t num_dirty_pages_init = migration_dirty_pages;
643     MigrationState *s = migrate_get_current();
644     int64_t end_time;
645     int64_t bytes_xfer_now;
646     static uint64_t xbzrle_cache_miss_prev;
647     static uint64_t iterations_prev;
648 
649     bitmap_sync_count++;
650 
651     if (!bytes_xfer_prev) {
652         bytes_xfer_prev = ram_bytes_transferred();
653     }
654 
655     if (!start_time) {
656         start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
657     }
658 
659     trace_migration_bitmap_sync_start();
660     address_space_sync_dirty_bitmap(&address_space_memory);
661 
662     rcu_read_lock();
663     QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
664         migration_bitmap_sync_range(block->mr->ram_addr, block->used_length);
665     }
666     rcu_read_unlock();
667 
668     trace_migration_bitmap_sync_end(migration_dirty_pages
669                                     - num_dirty_pages_init);
670     num_dirty_pages_period += migration_dirty_pages - num_dirty_pages_init;
671     end_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
672 
673     /* more than 1 second = 1000 millisecons */
674     if (end_time > start_time + 1000) {
675         if (migrate_auto_converge()) {
676             /* The following detection logic can be refined later. For now:
677                Check to see if the dirtied bytes is 50% more than the approx.
678                amount of bytes that just got transferred since the last time we
679                were in this routine. If that happens >N times (for now N==4)
680                we turn on the throttle down logic */
681             bytes_xfer_now = ram_bytes_transferred();
682             if (s->dirty_pages_rate &&
683                (num_dirty_pages_period * TARGET_PAGE_SIZE >
684                    (bytes_xfer_now - bytes_xfer_prev)/2) &&
685                (dirty_rate_high_cnt++ > 4)) {
686                     trace_migration_throttle();
687                     mig_throttle_on = true;
688                     dirty_rate_high_cnt = 0;
689              }
690              bytes_xfer_prev = bytes_xfer_now;
691         } else {
692              mig_throttle_on = false;
693         }
694         if (migrate_use_xbzrle()) {
695             if (iterations_prev != 0) {
696                 acct_info.xbzrle_cache_miss_rate =
697                    (double)(acct_info.xbzrle_cache_miss -
698                             xbzrle_cache_miss_prev) /
699                    (acct_info.iterations - iterations_prev);
700             }
701             iterations_prev = acct_info.iterations;
702             xbzrle_cache_miss_prev = acct_info.xbzrle_cache_miss;
703         }
704         s->dirty_pages_rate = num_dirty_pages_period * 1000
705             / (end_time - start_time);
706         s->dirty_bytes_rate = s->dirty_pages_rate * TARGET_PAGE_SIZE;
707         start_time = end_time;
708         num_dirty_pages_period = 0;
709         s->dirty_sync_count = bitmap_sync_count;
710     }
711 }
712 
713 /**
714  * ram_save_page: Send the given page to the stream
715  *
716  * Returns: Number of pages written.
717  *
718  * @f: QEMUFile where to send the data
719  * @block: block that contains the page we want to send
720  * @offset: offset inside the block for the page
721  * @last_stage: if we are at the completion stage
722  * @bytes_transferred: increase it with the number of transferred bytes
723  */
724 static int ram_save_page(QEMUFile *f, RAMBlock* block, ram_addr_t offset,
725                          bool last_stage, uint64_t *bytes_transferred)
726 {
727     int pages = -1;
728     uint64_t bytes_xmit;
729     ram_addr_t current_addr;
730     MemoryRegion *mr = block->mr;
731     uint8_t *p;
732     int ret;
733     bool send_async = true;
734 
735     p = memory_region_get_ram_ptr(mr) + offset;
736 
737     /* In doubt sent page as normal */
738     bytes_xmit = 0;
739     ret = ram_control_save_page(f, block->offset,
740                            offset, TARGET_PAGE_SIZE, &bytes_xmit);
741     if (bytes_xmit) {
742         *bytes_transferred += bytes_xmit;
743         pages = 1;
744     }
745 
746     XBZRLE_cache_lock();
747 
748     current_addr = block->offset + offset;
749 
750     if (block == last_sent_block) {
751         offset |= RAM_SAVE_FLAG_CONTINUE;
752     }
753     if (ret != RAM_SAVE_CONTROL_NOT_SUPP) {
754         if (ret != RAM_SAVE_CONTROL_DELAYED) {
755             if (bytes_xmit > 0) {
756                 acct_info.norm_pages++;
757             } else if (bytes_xmit == 0) {
758                 acct_info.dup_pages++;
759             }
760         }
761     } else if (is_zero_range(p, TARGET_PAGE_SIZE)) {
762         acct_info.dup_pages++;
763         *bytes_transferred += save_page_header(f, block,
764                                                offset | RAM_SAVE_FLAG_COMPRESS);
765         qemu_put_byte(f, 0);
766         *bytes_transferred += 1;
767         pages = 1;
768         /* Must let xbzrle know, otherwise a previous (now 0'd) cached
769          * page would be stale
770          */
771         xbzrle_cache_zero_page(current_addr);
772     } else if (!ram_bulk_stage && migrate_use_xbzrle()) {
773         pages = save_xbzrle_page(f, &p, current_addr, block,
774                                  offset, last_stage, bytes_transferred);
775         if (!last_stage) {
776             /* Can't send this cached data async, since the cache page
777              * might get updated before it gets to the wire
778              */
779             send_async = false;
780         }
781     }
782 
783     /* XBZRLE overflow or normal page */
784     if (pages == -1) {
785         *bytes_transferred += save_page_header(f, block,
786                                                offset | RAM_SAVE_FLAG_PAGE);
787         if (send_async) {
788             qemu_put_buffer_async(f, p, TARGET_PAGE_SIZE);
789         } else {
790             qemu_put_buffer(f, p, TARGET_PAGE_SIZE);
791         }
792         *bytes_transferred += TARGET_PAGE_SIZE;
793         pages = 1;
794         acct_info.norm_pages++;
795     }
796 
797     XBZRLE_cache_unlock();
798 
799     return pages;
800 }
801 
802 /**
803  * ram_save_compressed_page: compress the given page and send it to the stream
804  *
805  * Returns: Number of pages written.
806  *
807  * @f: QEMUFile where to send the data
808  * @block: block that contains the page we want to send
809  * @offset: offset inside the block for the page
810  * @last_stage: if we are at the completion stage
811  * @bytes_transferred: increase it with the number of transferred bytes
812  */
813 static int ram_save_compressed_page(QEMUFile *f, RAMBlock *block,
814                                     ram_addr_t offset, bool last_stage,
815                                     uint64_t *bytes_transferred)
816 {
817     int pages = -1;
818 
819     /* To be done*/
820 
821     return pages;
822 }
823 
824 /**
825  * ram_find_and_save_block: Finds a dirty page and sends it to f
826  *
827  * Called within an RCU critical section.
828  *
829  * Returns:  The number of pages written
830  *           0 means no dirty pages
831  *
832  * @f: QEMUFile where to send the data
833  * @last_stage: if we are at the completion stage
834  * @bytes_transferred: increase it with the number of transferred bytes
835  */
836 
837 static int ram_find_and_save_block(QEMUFile *f, bool last_stage,
838                                    uint64_t *bytes_transferred)
839 {
840     RAMBlock *block = last_seen_block;
841     ram_addr_t offset = last_offset;
842     bool complete_round = false;
843     int pages = 0;
844     MemoryRegion *mr;
845 
846     if (!block)
847         block = QLIST_FIRST_RCU(&ram_list.blocks);
848 
849     while (true) {
850         mr = block->mr;
851         offset = migration_bitmap_find_and_reset_dirty(mr, offset);
852         if (complete_round && block == last_seen_block &&
853             offset >= last_offset) {
854             break;
855         }
856         if (offset >= block->used_length) {
857             offset = 0;
858             block = QLIST_NEXT_RCU(block, next);
859             if (!block) {
860                 block = QLIST_FIRST_RCU(&ram_list.blocks);
861                 complete_round = true;
862                 ram_bulk_stage = false;
863             }
864         } else {
865             if (migrate_use_compression()) {
866                 pages = ram_save_compressed_page(f, block, offset, last_stage,
867                                                  bytes_transferred);
868             } else {
869                 pages = ram_save_page(f, block, offset, last_stage,
870                                       bytes_transferred);
871             }
872 
873             /* if page is unmodified, continue to the next */
874             if (pages > 0) {
875                 last_sent_block = block;
876                 break;
877             }
878         }
879     }
880 
881     last_seen_block = block;
882     last_offset = offset;
883 
884     return pages;
885 }
886 
887 static uint64_t bytes_transferred;
888 
889 void acct_update_position(QEMUFile *f, size_t size, bool zero)
890 {
891     uint64_t pages = size / TARGET_PAGE_SIZE;
892     if (zero) {
893         acct_info.dup_pages += pages;
894     } else {
895         acct_info.norm_pages += pages;
896         bytes_transferred += size;
897         qemu_update_position(f, size);
898     }
899 }
900 
901 static ram_addr_t ram_save_remaining(void)
902 {
903     return migration_dirty_pages;
904 }
905 
906 uint64_t ram_bytes_remaining(void)
907 {
908     return ram_save_remaining() * TARGET_PAGE_SIZE;
909 }
910 
911 uint64_t ram_bytes_transferred(void)
912 {
913     return bytes_transferred;
914 }
915 
916 uint64_t ram_bytes_total(void)
917 {
918     RAMBlock *block;
919     uint64_t total = 0;
920 
921     rcu_read_lock();
922     QLIST_FOREACH_RCU(block, &ram_list.blocks, next)
923         total += block->used_length;
924     rcu_read_unlock();
925     return total;
926 }
927 
928 void free_xbzrle_decoded_buf(void)
929 {
930     g_free(xbzrle_decoded_buf);
931     xbzrle_decoded_buf = NULL;
932 }
933 
934 static void migration_end(void)
935 {
936     if (migration_bitmap) {
937         memory_global_dirty_log_stop();
938         g_free(migration_bitmap);
939         migration_bitmap = NULL;
940     }
941 
942     XBZRLE_cache_lock();
943     if (XBZRLE.cache) {
944         cache_fini(XBZRLE.cache);
945         g_free(XBZRLE.encoded_buf);
946         g_free(XBZRLE.current_buf);
947         XBZRLE.cache = NULL;
948         XBZRLE.encoded_buf = NULL;
949         XBZRLE.current_buf = NULL;
950     }
951     XBZRLE_cache_unlock();
952 }
953 
954 static void ram_migration_cancel(void *opaque)
955 {
956     migration_end();
957 }
958 
959 static void reset_ram_globals(void)
960 {
961     last_seen_block = NULL;
962     last_sent_block = NULL;
963     last_offset = 0;
964     last_version = ram_list.version;
965     ram_bulk_stage = true;
966 }
967 
968 #define MAX_WAIT 50 /* ms, half buffered_file limit */
969 
970 
971 /* Each of ram_save_setup, ram_save_iterate and ram_save_complete has
972  * long-running RCU critical section.  When rcu-reclaims in the code
973  * start to become numerous it will be necessary to reduce the
974  * granularity of these critical sections.
975  */
976 
977 static int ram_save_setup(QEMUFile *f, void *opaque)
978 {
979     RAMBlock *block;
980     int64_t ram_bitmap_pages; /* Size of bitmap in pages, including gaps */
981 
982     mig_throttle_on = false;
983     dirty_rate_high_cnt = 0;
984     bitmap_sync_count = 0;
985     migration_bitmap_sync_init();
986 
987     if (migrate_use_xbzrle()) {
988         XBZRLE_cache_lock();
989         XBZRLE.cache = cache_init(migrate_xbzrle_cache_size() /
990                                   TARGET_PAGE_SIZE,
991                                   TARGET_PAGE_SIZE);
992         if (!XBZRLE.cache) {
993             XBZRLE_cache_unlock();
994             error_report("Error creating cache");
995             return -1;
996         }
997         XBZRLE_cache_unlock();
998 
999         /* We prefer not to abort if there is no memory */
1000         XBZRLE.encoded_buf = g_try_malloc0(TARGET_PAGE_SIZE);
1001         if (!XBZRLE.encoded_buf) {
1002             error_report("Error allocating encoded_buf");
1003             return -1;
1004         }
1005 
1006         XBZRLE.current_buf = g_try_malloc(TARGET_PAGE_SIZE);
1007         if (!XBZRLE.current_buf) {
1008             error_report("Error allocating current_buf");
1009             g_free(XBZRLE.encoded_buf);
1010             XBZRLE.encoded_buf = NULL;
1011             return -1;
1012         }
1013 
1014         acct_clear();
1015     }
1016 
1017     /* iothread lock needed for ram_list.dirty_memory[] */
1018     qemu_mutex_lock_iothread();
1019     qemu_mutex_lock_ramlist();
1020     rcu_read_lock();
1021     bytes_transferred = 0;
1022     reset_ram_globals();
1023 
1024     ram_bitmap_pages = last_ram_offset() >> TARGET_PAGE_BITS;
1025     migration_bitmap = bitmap_new(ram_bitmap_pages);
1026     bitmap_set(migration_bitmap, 0, ram_bitmap_pages);
1027 
1028     /*
1029      * Count the total number of pages used by ram blocks not including any
1030      * gaps due to alignment or unplugs.
1031      */
1032     migration_dirty_pages = ram_bytes_total() >> TARGET_PAGE_BITS;
1033 
1034     memory_global_dirty_log_start();
1035     migration_bitmap_sync();
1036     qemu_mutex_unlock_ramlist();
1037     qemu_mutex_unlock_iothread();
1038 
1039     qemu_put_be64(f, ram_bytes_total() | RAM_SAVE_FLAG_MEM_SIZE);
1040 
1041     QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
1042         qemu_put_byte(f, strlen(block->idstr));
1043         qemu_put_buffer(f, (uint8_t *)block->idstr, strlen(block->idstr));
1044         qemu_put_be64(f, block->used_length);
1045     }
1046 
1047     rcu_read_unlock();
1048 
1049     ram_control_before_iterate(f, RAM_CONTROL_SETUP);
1050     ram_control_after_iterate(f, RAM_CONTROL_SETUP);
1051 
1052     qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
1053 
1054     return 0;
1055 }
1056 
1057 static int ram_save_iterate(QEMUFile *f, void *opaque)
1058 {
1059     int ret;
1060     int i;
1061     int64_t t0;
1062     int pages_sent = 0;
1063 
1064     rcu_read_lock();
1065     if (ram_list.version != last_version) {
1066         reset_ram_globals();
1067     }
1068 
1069     /* Read version before ram_list.blocks */
1070     smp_rmb();
1071 
1072     ram_control_before_iterate(f, RAM_CONTROL_ROUND);
1073 
1074     t0 = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
1075     i = 0;
1076     while ((ret = qemu_file_rate_limit(f)) == 0) {
1077         int pages;
1078 
1079         pages = ram_find_and_save_block(f, false, &bytes_transferred);
1080         /* no more pages to sent */
1081         if (pages == 0) {
1082             break;
1083         }
1084         pages_sent += pages;
1085         acct_info.iterations++;
1086         check_guest_throttling();
1087         /* we want to check in the 1st loop, just in case it was the 1st time
1088            and we had to sync the dirty bitmap.
1089            qemu_get_clock_ns() is a bit expensive, so we only check each some
1090            iterations
1091         */
1092         if ((i & 63) == 0) {
1093             uint64_t t1 = (qemu_clock_get_ns(QEMU_CLOCK_REALTIME) - t0) / 1000000;
1094             if (t1 > MAX_WAIT) {
1095                 DPRINTF("big wait: %" PRIu64 " milliseconds, %d iterations\n",
1096                         t1, i);
1097                 break;
1098             }
1099         }
1100         i++;
1101     }
1102     rcu_read_unlock();
1103 
1104     /*
1105      * Must occur before EOS (or any QEMUFile operation)
1106      * because of RDMA protocol.
1107      */
1108     ram_control_after_iterate(f, RAM_CONTROL_ROUND);
1109 
1110     qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
1111     bytes_transferred += 8;
1112 
1113     ret = qemu_file_get_error(f);
1114     if (ret < 0) {
1115         return ret;
1116     }
1117 
1118     return pages_sent;
1119 }
1120 
1121 /* Called with iothread lock */
1122 static int ram_save_complete(QEMUFile *f, void *opaque)
1123 {
1124     rcu_read_lock();
1125 
1126     migration_bitmap_sync();
1127 
1128     ram_control_before_iterate(f, RAM_CONTROL_FINISH);
1129 
1130     /* try transferring iterative blocks of memory */
1131 
1132     /* flush all remaining blocks regardless of rate limiting */
1133     while (true) {
1134         int pages;
1135 
1136         pages = ram_find_and_save_block(f, true, &bytes_transferred);
1137         /* no more blocks to sent */
1138         if (pages == 0) {
1139             break;
1140         }
1141     }
1142 
1143     ram_control_after_iterate(f, RAM_CONTROL_FINISH);
1144     migration_end();
1145 
1146     rcu_read_unlock();
1147     qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
1148 
1149     return 0;
1150 }
1151 
1152 static uint64_t ram_save_pending(QEMUFile *f, void *opaque, uint64_t max_size)
1153 {
1154     uint64_t remaining_size;
1155 
1156     remaining_size = ram_save_remaining() * TARGET_PAGE_SIZE;
1157 
1158     if (remaining_size < max_size) {
1159         qemu_mutex_lock_iothread();
1160         rcu_read_lock();
1161         migration_bitmap_sync();
1162         rcu_read_unlock();
1163         qemu_mutex_unlock_iothread();
1164         remaining_size = ram_save_remaining() * TARGET_PAGE_SIZE;
1165     }
1166     return remaining_size;
1167 }
1168 
1169 static int load_xbzrle(QEMUFile *f, ram_addr_t addr, void *host)
1170 {
1171     unsigned int xh_len;
1172     int xh_flags;
1173 
1174     if (!xbzrle_decoded_buf) {
1175         xbzrle_decoded_buf = g_malloc(TARGET_PAGE_SIZE);
1176     }
1177 
1178     /* extract RLE header */
1179     xh_flags = qemu_get_byte(f);
1180     xh_len = qemu_get_be16(f);
1181 
1182     if (xh_flags != ENCODING_FLAG_XBZRLE) {
1183         error_report("Failed to load XBZRLE page - wrong compression!");
1184         return -1;
1185     }
1186 
1187     if (xh_len > TARGET_PAGE_SIZE) {
1188         error_report("Failed to load XBZRLE page - len overflow!");
1189         return -1;
1190     }
1191     /* load data and decode */
1192     qemu_get_buffer(f, xbzrle_decoded_buf, xh_len);
1193 
1194     /* decode RLE */
1195     if (xbzrle_decode_buffer(xbzrle_decoded_buf, xh_len, host,
1196                              TARGET_PAGE_SIZE) == -1) {
1197         error_report("Failed to load XBZRLE page - decode error!");
1198         return -1;
1199     }
1200 
1201     return 0;
1202 }
1203 
1204 /* Must be called from within a rcu critical section.
1205  * Returns a pointer from within the RCU-protected ram_list.
1206  */
1207 static inline void *host_from_stream_offset(QEMUFile *f,
1208                                             ram_addr_t offset,
1209                                             int flags)
1210 {
1211     static RAMBlock *block = NULL;
1212     char id[256];
1213     uint8_t len;
1214 
1215     if (flags & RAM_SAVE_FLAG_CONTINUE) {
1216         if (!block || block->max_length <= offset) {
1217             error_report("Ack, bad migration stream!");
1218             return NULL;
1219         }
1220 
1221         return memory_region_get_ram_ptr(block->mr) + offset;
1222     }
1223 
1224     len = qemu_get_byte(f);
1225     qemu_get_buffer(f, (uint8_t *)id, len);
1226     id[len] = 0;
1227 
1228     QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
1229         if (!strncmp(id, block->idstr, sizeof(id)) &&
1230             block->max_length > offset) {
1231             return memory_region_get_ram_ptr(block->mr) + offset;
1232         }
1233     }
1234 
1235     error_report("Can't find block %s!", id);
1236     return NULL;
1237 }
1238 
1239 /*
1240  * If a page (or a whole RDMA chunk) has been
1241  * determined to be zero, then zap it.
1242  */
1243 void ram_handle_compressed(void *host, uint8_t ch, uint64_t size)
1244 {
1245     if (ch != 0 || !is_zero_range(host, size)) {
1246         memset(host, ch, size);
1247     }
1248 }
1249 
1250 static void *do_data_decompress(void *opaque)
1251 {
1252     while (!quit_decomp_thread) {
1253         /* To be done */
1254     }
1255 
1256     return NULL;
1257 }
1258 
1259 void migrate_decompress_threads_create(void)
1260 {
1261     int i, thread_count;
1262 
1263     thread_count = migrate_decompress_threads();
1264     decompress_threads = g_new0(QemuThread, thread_count);
1265     decomp_param = g_new0(DecompressParam, thread_count);
1266     compressed_data_buf = g_malloc0(compressBound(TARGET_PAGE_SIZE));
1267     quit_decomp_thread = false;
1268     for (i = 0; i < thread_count; i++) {
1269         qemu_thread_create(decompress_threads + i, "decompress",
1270                            do_data_decompress, decomp_param + i,
1271                            QEMU_THREAD_JOINABLE);
1272     }
1273 }
1274 
1275 void migrate_decompress_threads_join(void)
1276 {
1277     int i, thread_count;
1278 
1279     quit_decomp_thread = true;
1280     thread_count = migrate_decompress_threads();
1281     for (i = 0; i < thread_count; i++) {
1282         qemu_thread_join(decompress_threads + i);
1283     }
1284     g_free(decompress_threads);
1285     g_free(decomp_param);
1286     g_free(compressed_data_buf);
1287     decompress_threads = NULL;
1288     decomp_param = NULL;
1289     compressed_data_buf = NULL;
1290 }
1291 
1292 static void decompress_data_with_multi_threads(uint8_t *compbuf,
1293                                                void *host, int len)
1294 {
1295     /* To be done */
1296 }
1297 
1298 static int ram_load(QEMUFile *f, void *opaque, int version_id)
1299 {
1300     int flags = 0, ret = 0;
1301     static uint64_t seq_iter;
1302     int len = 0;
1303 
1304     seq_iter++;
1305 
1306     if (version_id != 4) {
1307         ret = -EINVAL;
1308     }
1309 
1310     /* This RCU critical section can be very long running.
1311      * When RCU reclaims in the code start to become numerous,
1312      * it will be necessary to reduce the granularity of this
1313      * critical section.
1314      */
1315     rcu_read_lock();
1316     while (!ret && !(flags & RAM_SAVE_FLAG_EOS)) {
1317         ram_addr_t addr, total_ram_bytes;
1318         void *host;
1319         uint8_t ch;
1320 
1321         addr = qemu_get_be64(f);
1322         flags = addr & ~TARGET_PAGE_MASK;
1323         addr &= TARGET_PAGE_MASK;
1324 
1325         switch (flags & ~RAM_SAVE_FLAG_CONTINUE) {
1326         case RAM_SAVE_FLAG_MEM_SIZE:
1327             /* Synchronize RAM block list */
1328             total_ram_bytes = addr;
1329             while (!ret && total_ram_bytes) {
1330                 RAMBlock *block;
1331                 uint8_t len;
1332                 char id[256];
1333                 ram_addr_t length;
1334 
1335                 len = qemu_get_byte(f);
1336                 qemu_get_buffer(f, (uint8_t *)id, len);
1337                 id[len] = 0;
1338                 length = qemu_get_be64(f);
1339 
1340                 QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
1341                     if (!strncmp(id, block->idstr, sizeof(id))) {
1342                         if (length != block->used_length) {
1343                             Error *local_err = NULL;
1344 
1345                             ret = qemu_ram_resize(block->offset, length, &local_err);
1346                             if (local_err) {
1347                                 error_report_err(local_err);
1348                             }
1349                         }
1350                         break;
1351                     }
1352                 }
1353 
1354                 if (!block) {
1355                     error_report("Unknown ramblock \"%s\", cannot "
1356                                  "accept migration", id);
1357                     ret = -EINVAL;
1358                 }
1359 
1360                 total_ram_bytes -= length;
1361             }
1362             break;
1363         case RAM_SAVE_FLAG_COMPRESS:
1364             host = host_from_stream_offset(f, addr, flags);
1365             if (!host) {
1366                 error_report("Illegal RAM offset " RAM_ADDR_FMT, addr);
1367                 ret = -EINVAL;
1368                 break;
1369             }
1370             ch = qemu_get_byte(f);
1371             ram_handle_compressed(host, ch, TARGET_PAGE_SIZE);
1372             break;
1373         case RAM_SAVE_FLAG_PAGE:
1374             host = host_from_stream_offset(f, addr, flags);
1375             if (!host) {
1376                 error_report("Illegal RAM offset " RAM_ADDR_FMT, addr);
1377                 ret = -EINVAL;
1378                 break;
1379             }
1380             qemu_get_buffer(f, host, TARGET_PAGE_SIZE);
1381             break;
1382         case RAM_SAVE_FLAG_COMPRESS_PAGE:
1383             host = host_from_stream_offset(f, addr, flags);
1384             if (!host) {
1385                 error_report("Invalid RAM offset " RAM_ADDR_FMT, addr);
1386                 ret = -EINVAL;
1387                 break;
1388             }
1389 
1390             len = qemu_get_be32(f);
1391             if (len < 0 || len > compressBound(TARGET_PAGE_SIZE)) {
1392                 error_report("Invalid compressed data length: %d", len);
1393                 ret = -EINVAL;
1394                 break;
1395             }
1396             qemu_get_buffer(f, compressed_data_buf, len);
1397             decompress_data_with_multi_threads(compressed_data_buf, host, len);
1398             break;
1399         case RAM_SAVE_FLAG_XBZRLE:
1400             host = host_from_stream_offset(f, addr, flags);
1401             if (!host) {
1402                 error_report("Illegal RAM offset " RAM_ADDR_FMT, addr);
1403                 ret = -EINVAL;
1404                 break;
1405             }
1406             if (load_xbzrle(f, addr, host) < 0) {
1407                 error_report("Failed to decompress XBZRLE page at "
1408                              RAM_ADDR_FMT, addr);
1409                 ret = -EINVAL;
1410                 break;
1411             }
1412             break;
1413         case RAM_SAVE_FLAG_EOS:
1414             /* normal exit */
1415             break;
1416         default:
1417             if (flags & RAM_SAVE_FLAG_HOOK) {
1418                 ram_control_load_hook(f, flags);
1419             } else {
1420                 error_report("Unknown combination of migration flags: %#x",
1421                              flags);
1422                 ret = -EINVAL;
1423             }
1424         }
1425         if (!ret) {
1426             ret = qemu_file_get_error(f);
1427         }
1428     }
1429 
1430     rcu_read_unlock();
1431     DPRINTF("Completed load of VM with exit code %d seq iteration "
1432             "%" PRIu64 "\n", ret, seq_iter);
1433     return ret;
1434 }
1435 
1436 static SaveVMHandlers savevm_ram_handlers = {
1437     .save_live_setup = ram_save_setup,
1438     .save_live_iterate = ram_save_iterate,
1439     .save_live_complete = ram_save_complete,
1440     .save_live_pending = ram_save_pending,
1441     .load_state = ram_load,
1442     .cancel = ram_migration_cancel,
1443 };
1444 
1445 void ram_mig_init(void)
1446 {
1447     qemu_mutex_init(&XBZRLE.lock);
1448     register_savevm_live(NULL, "ram", 0, 4, &savevm_ram_handlers, NULL);
1449 }
1450 
1451 struct soundhw {
1452     const char *name;
1453     const char *descr;
1454     int enabled;
1455     int isa;
1456     union {
1457         int (*init_isa) (ISABus *bus);
1458         int (*init_pci) (PCIBus *bus);
1459     } init;
1460 };
1461 
1462 static struct soundhw soundhw[9];
1463 static int soundhw_count;
1464 
1465 void isa_register_soundhw(const char *name, const char *descr,
1466                           int (*init_isa)(ISABus *bus))
1467 {
1468     assert(soundhw_count < ARRAY_SIZE(soundhw) - 1);
1469     soundhw[soundhw_count].name = name;
1470     soundhw[soundhw_count].descr = descr;
1471     soundhw[soundhw_count].isa = 1;
1472     soundhw[soundhw_count].init.init_isa = init_isa;
1473     soundhw_count++;
1474 }
1475 
1476 void pci_register_soundhw(const char *name, const char *descr,
1477                           int (*init_pci)(PCIBus *bus))
1478 {
1479     assert(soundhw_count < ARRAY_SIZE(soundhw) - 1);
1480     soundhw[soundhw_count].name = name;
1481     soundhw[soundhw_count].descr = descr;
1482     soundhw[soundhw_count].isa = 0;
1483     soundhw[soundhw_count].init.init_pci = init_pci;
1484     soundhw_count++;
1485 }
1486 
1487 void select_soundhw(const char *optarg)
1488 {
1489     struct soundhw *c;
1490 
1491     if (is_help_option(optarg)) {
1492     show_valid_cards:
1493 
1494         if (soundhw_count) {
1495              printf("Valid sound card names (comma separated):\n");
1496              for (c = soundhw; c->name; ++c) {
1497                  printf ("%-11s %s\n", c->name, c->descr);
1498              }
1499              printf("\n-soundhw all will enable all of the above\n");
1500         } else {
1501              printf("Machine has no user-selectable audio hardware "
1502                     "(it may or may not have always-present audio hardware).\n");
1503         }
1504         exit(!is_help_option(optarg));
1505     }
1506     else {
1507         size_t l;
1508         const char *p;
1509         char *e;
1510         int bad_card = 0;
1511 
1512         if (!strcmp(optarg, "all")) {
1513             for (c = soundhw; c->name; ++c) {
1514                 c->enabled = 1;
1515             }
1516             return;
1517         }
1518 
1519         p = optarg;
1520         while (*p) {
1521             e = strchr(p, ',');
1522             l = !e ? strlen(p) : (size_t) (e - p);
1523 
1524             for (c = soundhw; c->name; ++c) {
1525                 if (!strncmp(c->name, p, l) && !c->name[l]) {
1526                     c->enabled = 1;
1527                     break;
1528                 }
1529             }
1530 
1531             if (!c->name) {
1532                 if (l > 80) {
1533                     error_report("Unknown sound card name (too big to show)");
1534                 }
1535                 else {
1536                     error_report("Unknown sound card name `%.*s'",
1537                                  (int) l, p);
1538                 }
1539                 bad_card = 1;
1540             }
1541             p += l + (e != NULL);
1542         }
1543 
1544         if (bad_card) {
1545             goto show_valid_cards;
1546         }
1547     }
1548 }
1549 
1550 void audio_init(void)
1551 {
1552     struct soundhw *c;
1553     ISABus *isa_bus = (ISABus *) object_resolve_path_type("", TYPE_ISA_BUS, NULL);
1554     PCIBus *pci_bus = (PCIBus *) object_resolve_path_type("", TYPE_PCI_BUS, NULL);
1555 
1556     for (c = soundhw; c->name; ++c) {
1557         if (c->enabled) {
1558             if (c->isa) {
1559                 if (!isa_bus) {
1560                     error_report("ISA bus not available for %s", c->name);
1561                     exit(1);
1562                 }
1563                 c->init.init_isa(isa_bus);
1564             } else {
1565                 if (!pci_bus) {
1566                     error_report("PCI bus not available for %s", c->name);
1567                     exit(1);
1568                 }
1569                 c->init.init_pci(pci_bus);
1570             }
1571         }
1572     }
1573 }
1574 
1575 int qemu_uuid_parse(const char *str, uint8_t *uuid)
1576 {
1577     int ret;
1578 
1579     if (strlen(str) != 36) {
1580         return -1;
1581     }
1582 
1583     ret = sscanf(str, UUID_FMT, &uuid[0], &uuid[1], &uuid[2], &uuid[3],
1584                  &uuid[4], &uuid[5], &uuid[6], &uuid[7], &uuid[8], &uuid[9],
1585                  &uuid[10], &uuid[11], &uuid[12], &uuid[13], &uuid[14],
1586                  &uuid[15]);
1587 
1588     if (ret != 16) {
1589         return -1;
1590     }
1591     return 0;
1592 }
1593 
1594 void do_acpitable_option(const QemuOpts *opts)
1595 {
1596 #ifdef TARGET_I386
1597     Error *err = NULL;
1598 
1599     acpi_table_add(opts, &err);
1600     if (err) {
1601         error_report("Wrong acpi table provided: %s",
1602                      error_get_pretty(err));
1603         error_free(err);
1604         exit(1);
1605     }
1606 #endif
1607 }
1608 
1609 void do_smbios_option(QemuOpts *opts)
1610 {
1611 #ifdef TARGET_I386
1612     smbios_entry_add(opts);
1613 #endif
1614 }
1615 
1616 void cpudef_init(void)
1617 {
1618 #if defined(cpudef_setup)
1619     cpudef_setup(); /* parse cpu definitions in target config file */
1620 #endif
1621 }
1622 
1623 int kvm_available(void)
1624 {
1625 #ifdef CONFIG_KVM
1626     return 1;
1627 #else
1628     return 0;
1629 #endif
1630 }
1631 
1632 int xen_available(void)
1633 {
1634 #ifdef CONFIG_XEN
1635     return 1;
1636 #else
1637     return 0;
1638 #endif
1639 }
1640 
1641 
1642 TargetInfo *qmp_query_target(Error **errp)
1643 {
1644     TargetInfo *info = g_malloc0(sizeof(*info));
1645 
1646     info->arch = g_strdup(TARGET_NAME);
1647 
1648     return info;
1649 }
1650 
1651 /* Stub function that's gets run on the vcpu when its brought out of the
1652    VM to run inside qemu via async_run_on_cpu()*/
1653 static void mig_sleep_cpu(void *opq)
1654 {
1655     qemu_mutex_unlock_iothread();
1656     g_usleep(30*1000);
1657     qemu_mutex_lock_iothread();
1658 }
1659 
1660 /* To reduce the dirty rate explicitly disallow the VCPUs from spending
1661    much time in the VM. The migration thread will try to catchup.
1662    Workload will experience a performance drop.
1663 */
1664 static void mig_throttle_guest_down(void)
1665 {
1666     CPUState *cpu;
1667 
1668     qemu_mutex_lock_iothread();
1669     CPU_FOREACH(cpu) {
1670         async_run_on_cpu(cpu, mig_sleep_cpu, NULL);
1671     }
1672     qemu_mutex_unlock_iothread();
1673 }
1674 
1675 static void check_guest_throttling(void)
1676 {
1677     static int64_t t0;
1678     int64_t        t1;
1679 
1680     if (!mig_throttle_on) {
1681         return;
1682     }
1683 
1684     if (!t0)  {
1685         t0 = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
1686         return;
1687     }
1688 
1689     t1 = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
1690 
1691     /* If it has been more than 40 ms since the last time the guest
1692      * was throttled then do it again.
1693      */
1694     if (40 < (t1-t0)/1000000) {
1695         mig_throttle_guest_down();
1696         t0 = t1;
1697     }
1698 }
1699